Hmm, next time, try telling her they are staffordshire or terriers - less scary a name. And a pitbull terrier is a terrier! After the child has petted and played with the pups, and you are leaving, you can then choose to say, "they are 'pitbull terriers,' but people get nervous because of the name, and I wanted your child to have a pleasant experience. They LOVE kids, and getting petted and this helps them with their socialization, too!"

Just my two cents.